Recoil adjusting device



May 1952. c w. MUSSER 3,035,494

RECOIL. ADJUSTING DEVICE Filed Jan. 26, 1960 Y1 VA VA W] Y] FIG. 2

FIG. 3

INVENTOR. C WALTON MUSSER L J. W

ATTORNEYS:

aired rates l atent 3,035,494 RECOIL ADJUSTING DEVICE C Walton Musser, Beverly, Mass., assignor to the United States of America as represented by the Secretary of the Army Filed Jan. 26, 1960, Ser. No. 4,829

1 Claim. (Cl. 89-1.7)

(Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes Without the payment to me of any royalty thereon.

This invention r'elates to weapons which function upon firing to produce a rearward blast of gas whereby recoil of the weapon is minimized. More particularly, it provides means which are operable to adjust such recoil to any desired value.

As is well understood by those skilled in the art, recoilless weapons normally include a barrel which is perforated to emit the gases by which the recoil is neutralized. Surrounding this barrel is a chamber which receives these gases and discharges them through a plurality of venturi openings at the breech end of the weapon.

Experience has shown that the recoil of the weapon is very sensitive to slight irregularities in the surface of the venturi openings. Due to difficulties in manufacture and to erosion during the use of the weapon, it is practically impossible to ensure that the venturi openings are such as to minimize recoil to the desired degree. The present invention avoids this difficulty by the provision of a ring or baflie which may be advanced into the chamber to any desired extent.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claim.

Referring to the drawings:

FIG. 1 is a sectional view of a recoilless weapon with the recoil compensator in its extreme rear position,

FIG. 2 is a similar view showing the recoil compensator somewhat advanced into the chamber, and

FIG. 3 is a cross-section taken on the line 3-3 of FIG. 1.

The recoilless weapon illustrated by these figures includes a barrel which has fixed to its breech end a chamber 11. Threaded into the rear end of the chamber 11 is a removable liner 12 which has a plurality of venturi openings 13. Threaded into the forward end of the member 12 is a conical ring 14 which may be adjusted longitudinally to different positions as indicated by FIG. 2.

The weapon illustrated by the various figures is adapted to fire a cartridge which includes a perforated casing 15 containing a propellant 16 and is closed at its forward end by a projectile 17, this cartridge being held in place by a breech member 18 of a well known type.

As previously indicated, the conical member 14 is arranged to be adjusted longitudinally. This adjustment functions to change the area of the path of the gases from the cartridge to the venturi openings. It also lengthens the travel of the gas immediately adjacent the head of the cartridge. This results in higher etficiency since more of the powder is burnt.

In use the recoil compensator 14 functions somewhat in the nature of a bafiie, since the powder gases, in order to get through the restricted area between the compensator 14 and the chamber 11, have to experience a drop in' pressure. This reduces the pressure of the gases at the point where they are entering the venturi openings. Since the pressure at the entrance of the venturi openings is somewhat lower than in the chamber, the mass rate of flow through the venturi openings is reduced. This permits the venturi openings to function even after it has eroded to a slightly larger size, thus by adjustment of compensator 14 forward and backward, the recoil can be adjusted to zero or to any other desired value.

Those familiar with recoilless guns will understand that this invention more than provides replaceable or adjustable venturi openings, by reason of the fact that the member 14 may be adjusted forwardly to compensate for erosion or wear in the venturi openings, thus prolonging the useful life of those openings. As shown in the drawing even though the forward and outer end portion of member 14 may be subject to erosion, nevertheless with forward adjustment its outer end may be brought closer to chamber wall 11 due to the slope of this wall. This member 14 is an advantage for two reasons. It functions as a preliminary constriction although erosion may occur at the outer end of member 14 and the adjacent wall 11. When member 14 wears and it is adjusted forwardly it cooperates with a new and nearer wall portion 11 where erosion has not been as serious. Another inherent advantage in member 14 which will be appreciated by those familiar with recoilless weapons is the fact that it functions to change the gas flow to an extent from laminar flow to turbulent flow, which latter counteracts the effect of erosion to a noticeable degree.

I claim:

A recoilless type weapon comprising in combination, a barrel, means forming a chamber fixed to a breech end portion of said barrel for reception axially thereto, a perforate casing of propellant spaced radially from said chamber forming means and communicating with said barrel, a removable liner fixed within a rear end portion of said chamber forming means, said liner being provided therein with a plurality of equally angularly spaced venturi openings, a breech member for holding a round within said weapon, said liner axially positioning the rear end of said perforate casing of propellant, and a member having a cylindrical portion threaded within said liner and being outside said perforate casing of propellant, said member having a forwardly and radially outwardly flaring ring portion forming with a rearwardly flaring portion of said chamber forming means a preliminary constriction through which propellant gases pass prior to passing rearwardly through said venturi openings, a wall of said chamber forming means adjacent the outer end of said flaring ring portion having an oppositely directed slope from that of said ring portion threaded within said liner, whereby said ring member may be adjustably moved forwardly to provide compensation for wear in the venturi openings.

References Cited in the file of this patent UNITED STATES PATENTS 2,489,747 Burney Nov. 29, 1949 2,489,748 Burney Nov. 29, 1949 2,537,063 Kroeger et al. Jan. 9, 1951 2,598,256 Hickman May 27, 1952 

